/*
 * hostapd / EAP-SIM (RFC 4186)
 * Copyright (c) 2005-2008, Jouni Malinen <j@w1.fi>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Alternatively, this software may be distributed under the terms of BSD
 * license.
 *
 * See README and COPYING for more details.
 */

#include "includes.h"

#include "common.h"
#include "eap_server/eap_i.h"
#include "eap_common/eap_sim_common.h"
#include "eap_server/eap_sim_db.h"


struct eap_sim_data {
        u8 mk[EAP_SIM_MK_LEN];
        u8 nonce_mt[EAP_SIM_NONCE_MT_LEN];
        u8 nonce_s[EAP_SIM_NONCE_S_LEN];
        u8 k_aut[EAP_SIM_K_AUT_LEN];
        u8 k_encr[EAP_SIM_K_ENCR_LEN];
        u8 msk[EAP_SIM_KEYING_DATA_LEN];
        u8 emsk[EAP_EMSK_LEN];
        u8 kc[EAP_SIM_MAX_CHAL][EAP_SIM_KC_LEN];
        u8 sres[EAP_SIM_MAX_CHAL][EAP_SIM_SRES_LEN];
        u8 rand[EAP_SIM_MAX_CHAL][GSM_RAND_LEN];
        int num_chal;
        enum {
                START, CHALLENGE, REAUTH, NOTIFICATION, SUCCESS, FAILURE
        } state;
        char *next_pseudonym;
        char *next_reauth_id;
        u16 counter;
        struct eap_sim_reauth *reauth;
        u16 notification;
        int use_result_ind;
};


static const char * eap_sim_state_txt(int state)
{
        switch (state) {
        case START:
                return "START";
        case CHALLENGE:
                return "CHALLENGE";
        case REAUTH:
                return "REAUTH";
        case SUCCESS:
                return "SUCCESS";
        case FAILURE:
                return "FAILURE";
        case NOTIFICATION:
                return "NOTIFICATION";
        default:
                return "Unknown?!";
        }
}


static void eap_sim_state(struct eap_sim_data *data, int state)
{
        wpa_printf(MSG_DEBUG, "EAP-SIM: %s -> %s",
                   eap_sim_state_txt(data->state),
                   eap_sim_state_txt(state));
        data->state = state;
}


static void * eap_sim_init(struct eap_sm *sm)
{
        struct eap_sim_data *data;

        if (sm->eap_sim_db_priv == NULL) {
                wpa_printf(MSG_WARNING, "EAP-SIM: eap_sim_db not configured");
                return NULL;
        }

        data = os_zalloc(sizeof(*data));
        if (data == NULL)
                return NULL;
        data->state = START;

        return data;
}


static void eap_sim_reset(struct eap_sm *sm, void *priv)
{
        struct eap_sim_data *data = priv;
        os_free(data->next_pseudonym);
        os_free(data->next_reauth_id);
        os_free(data);
}


static struct wpabuf * eap_sim_build_start(struct eap_sm *sm,
                                           struct eap_sim_data *data, u8 id)
{
        struct eap_sim_msg *msg;
        u8 ver[2];

        wpa_printf(MSG_DEBUG, "EAP-SIM: Generating Start");
        msg = eap_sim_msg_init(EAP_CODE_REQUEST, id, EAP_TYPE_SIM,
                               EAP_SIM_SUBTYPE_START);
        if (eap_sim_db_identity_known(sm->eap_sim_db_priv, sm->identity,
                                      sm->identity_len)) {
                wpa_printf(MSG_DEBUG, "   AT_PERMANENT_ID_REQ");
                eap_sim_msg_add(msg, EAP_SIM_AT_PERMANENT_ID_REQ, 0, NULL, 0);
        } else {
                /*
                 * RFC 4186, Chap. 4.2.4 recommends that identity from EAP is
                 * ignored and the SIM/Start is used to request the identity.
                 */
                wpa_printf(MSG_DEBUG, "   AT_ANY_ID_REQ");
                eap_sim_msg_add(msg, EAP_SIM_AT_ANY_ID_REQ, 0, NULL, 0);
        }
        wpa_printf(MSG_DEBUG, "   AT_VERSION_LIST");
        ver[0] = 0;
        ver[1] = EAP_SIM_VERSION;
        eap_sim_msg_add(msg, EAP_SIM_AT_VERSION_LIST, sizeof(ver),
                        ver, sizeof(ver));
        return eap_sim_msg_finish(msg, NULL, NULL, 0);
}


static int eap_sim_build_encr(struct eap_sm *sm, struct eap_sim_data *data,
                              struct eap_sim_msg *msg, u16 counter,
                              const u8 *nonce_s)
{
        os_free(data->next_pseudonym);
        data->next_pseudonym =
                eap_sim_db_get_next_pseudonym(sm->eap_sim_db_priv, 0);
        os_free(data->next_reauth_id);
        if (data->counter <= EAP_SIM_MAX_FAST_REAUTHS) {
                data->next_reauth_id =
                        eap_sim_db_get_next_reauth_id(sm->eap_sim_db_priv, 0);
        } else {
                wpa_printf(MSG_DEBUG, "EAP-SIM: Max fast re-authentication "
                           "count exceeded - force full authentication");
                data->next_reauth_id = NULL;
        }

        if (data->next_pseudonym == NULL && data->next_reauth_id == NULL &&
            counter == 0 && nonce_s == NULL)
                return 0;

        wpa_printf(MSG_DEBUG, "   AT_IV");
        wpa_printf(MSG_DEBUG, "   AT_ENCR_DATA");
        eap_sim_msg_add_encr_start(msg, EAP_SIM_AT_IV, EAP_SIM_AT_ENCR_DATA);

        if (counter > 0) {
                wpa_printf(MSG_DEBUG, "   *AT_COUNTER (%u)", counter);
                eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER, counter, NULL, 0);
        }

        if (nonce_s) {
                wpa_printf(MSG_DEBUG, "   *AT_NONCE_S");
                eap_sim_msg_add(msg, EAP_SIM_AT_NONCE_S, 0, nonce_s,
                                EAP_SIM_NONCE_S_LEN);
        }

        if (data->next_pseudonym) {
                wpa_printf(MSG_DEBUG, "   *AT_NEXT_PSEUDONYM (%s)",
                           data->next_pseudonym);
                eap_sim_msg_add(msg, EAP_SIM_AT_NEXT_PSEUDONYM,
                                os_strlen(data->next_pseudonym),
                                (u8 *) data->next_pseudonym,
                                os_strlen(data->next_pseudonym));
        }

        if (data->next_reauth_id) {
                wpa_printf(MSG_DEBUG, "   *AT_NEXT_REAUTH_ID (%s)",
                           data->next_reauth_id);
                eap_sim_msg_add(msg, EAP_SIM_AT_NEXT_REAUTH_ID,
                                os_strlen(data->next_reauth_id),
                                (u8 *) data->next_reauth_id,
                                os_strlen(data->next_reauth_id));
        }

        if (eap_sim_msg_add_encr_end(msg, data->k_encr, EAP_SIM_AT_PADDING)) {
                wpa_printf(MSG_WARNING, "EAP-SIM: Failed to encrypt "
                           "AT_ENCR_DATA");
                return -1;
        }

        return 0;
}


static struct wpabuf * eap_sim_build_challenge(struct eap_sm *sm,
                                               struct eap_sim_data *data,
                                               u8 id)
{
        struct eap_sim_msg *msg;

        wpa_printf(MSG_DEBUG, "EAP-SIM: Generating Challenge");
        msg = eap_sim_msg_init(EAP_CODE_REQUEST, id, EAP_TYPE_SIM,
                               EAP_SIM_SUBTYPE_CHALLENGE);
        wpa_printf(MSG_DEBUG, "   AT_RAND");
        eap_sim_msg_add(msg, EAP_SIM_AT_RAND, 0, (u8 *) data->rand,
                        data->num_chal * GSM_RAND_LEN);

        if (eap_sim_build_encr(sm, data, msg, 0, NULL)) {
                eap_sim_msg_free(msg);
                return NULL;
        }

        if (sm->eap_sim_aka_result_ind) {
                wpa_printf(MSG_DEBUG, "   AT_RESULT_IND");
                eap_sim_msg_add(msg, EAP_SIM_AT_RESULT_IND, 0, NULL, 0);
        }

        wpa_printf(MSG_DEBUG, "   AT_MAC");
        eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
        return eap_sim_msg_finish(msg, data->k_aut, data->nonce_mt,
                                  EAP_SIM_NONCE_MT_LEN);
}


static struct wpabuf * eap_sim_build_reauth(struct eap_sm *sm,
                                            struct eap_sim_data *data, u8 id)
{
        struct eap_sim_msg *msg;

        wpa_printf(MSG_DEBUG, "EAP-SIM: Generating Re-authentication");

        if (os_get_random(data->nonce_s, EAP_SIM_NONCE_S_LEN))
                return NULL;
        wpa_hexdump_key(MSG_MSGDUMP, "EAP-SIM: NONCE_S",
                        data->nonce_s, EAP_SIM_NONCE_S_LEN);

        eap_sim_derive_keys(data->mk, data->k_encr, data->k_aut, data->msk,
                            data->emsk);
        eap_sim_derive_keys_reauth(data->counter, sm->identity,
                                   sm->identity_len, data->nonce_s, data->mk,
                                   data->msk, data->emsk);

        msg = eap_sim_msg_init(EAP_CODE_REQUEST, id, EAP_TYPE_SIM,
                               EAP_SIM_SUBTYPE_REAUTHENTICATION);

        if (eap_sim_build_encr(sm, data, msg, data->counter, data->nonce_s)) {
                eap_sim_msg_free(msg);
                return NULL;
        }

        if (sm->eap_sim_aka_result_ind) {
                wpa_printf(MSG_DEBUG, "   AT_RESULT_IND");
                eap_sim_msg_add(msg, EAP_SIM_AT_RESULT_IND, 0, NULL, 0);
        }

        wpa_printf(MSG_DEBUG, "   AT_MAC");
        eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
        return eap_sim_msg_finish(msg, data->k_aut, NULL, 0);
}


static struct wpabuf * eap_sim_build_notification(struct eap_sm *sm,
                                                  struct eap_sim_data *data,
                                                  u8 id)
{
        struct eap_sim_msg *msg;

        wpa_printf(MSG_DEBUG, "EAP-SIM: Generating Notification");
        msg = eap_sim_msg_init(EAP_CODE_REQUEST, id, EAP_TYPE_SIM,
                               EAP_SIM_SUBTYPE_NOTIFICATION);
        wpa_printf(MSG_DEBUG, "   AT_NOTIFICATION (%d)", data->notification);
        eap_sim_msg_add(msg, EAP_SIM_AT_NOTIFICATION, data->notification,
                        NULL, 0);
        if (data->use_result_ind) {
                if (data->reauth) {
                        wpa_printf(MSG_DEBUG, "   AT_IV");
                        wpa_printf(MSG_DEBUG, "   AT_ENCR_DATA");
                        eap_sim_msg_add_encr_start(msg, EAP_SIM_AT_IV,
                                                   EAP_SIM_AT_ENCR_DATA);
                        wpa_printf(MSG_DEBUG, "   *AT_COUNTER (%u)",
                                   data->counter);
                        eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER, data->counter,
                                        NULL, 0);

                        if (eap_sim_msg_add_encr_end(msg, data->k_encr,
                                                     EAP_SIM_AT_PADDING)) {
                                wpa_printf(MSG_WARNING, "EAP-SIM: Failed to "
                                           "encrypt AT_ENCR_DATA");
                                eap_sim_msg_free(msg);
                                return NULL;
                        }
                }

                wpa_printf(MSG_DEBUG, "   AT_MAC");
                eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
        }
        return eap_sim_msg_finish(msg, data->k_aut, NULL, 0);
}


static struct wpabuf * eap_sim_buildReq(struct eap_sm *sm, void *priv, u8 id)
{
        struct eap_sim_data *data = priv;

        switch (data->state) {
        case START:
                return eap_sim_build_start(sm, data, id);
        case CHALLENGE:
                return eap_sim_build_challenge(sm, data, id);
        case REAUTH:
                return eap_sim_build_reauth(sm, data, id);
        case NOTIFICATION:
                return eap_sim_build_notification(sm, data, id);
        default:
                wpa_printf(MSG_DEBUG, "EAP-SIM: Unknown state %d in "
                           "buildReq", data->state);
                break;
        }
        return NULL;
}


static Boolean eap_sim_check(struct eap_sm *sm, void *priv,
                             struct wpabuf *respData)
{
        struct eap_sim_data *data = priv;
        const u8 *pos;
        size_t len;
        u8 subtype;

        pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_SIM, respData, &len);
        if (pos == NULL || len < 3) {
                wpa_printf(MSG_INFO, "EAP-SIM: Invalid frame");
                return TRUE;
        }
        subtype = *pos;

        if (subtype == EAP_SIM_SUBTYPE_CLIENT_ERROR)
                return FALSE;

        switch (data->state) {
        case START:
                if (subtype != EAP_SIM_SUBTYPE_START) {
                        wpa_printf(MSG_INFO, "EAP-SIM: Unexpected response "
                                   "subtype %d", subtype);
                        return TRUE;
                }
                break;
        case CHALLENGE:
                if (subtype != EAP_SIM_SUBTYPE_CHALLENGE) {
                        wpa_printf(MSG_INFO, "EAP-SIM: Unexpected response "
                                   "subtype %d", subtype);
                        return TRUE;
                }
                break;
        case REAUTH:
                if (subtype != EAP_SIM_SUBTYPE_REAUTHENTICATION) {
                        wpa_printf(MSG_INFO, "EAP-SIM: Unexpected response "
                                   "subtype %d", subtype);
                        return TRUE;
                }
                break;
        case NOTIFICATION:
                if (subtype != EAP_SIM_SUBTYPE_NOTIFICATION) {
                        wpa_printf(MSG_INFO, "EAP-SIM: Unexpected response "
                                   "subtype %d", subtype);
                        return TRUE;
                }
                break;
        default:
                wpa_printf(MSG_INFO, "EAP-SIM: Unexpected state (%d) for "
                           "processing a response", data->state);
                return TRUE;
        }

        return FALSE;
}


static int eap_sim_supported_ver(struct eap_sim_data *data, int version)
{
        return version == EAP_SIM_VERSION;
}


static void eap_sim_process_start(struct eap_sm *sm,
                                  struct eap_sim_data *data,
                                  struct wpabuf *respData,
                                  struct eap_sim_attrs *attr)
{
        const u8 *identity;
        size_t identity_len;
        u8 ver_list[2];

        wpa_printf(MSG_DEBUG, "EAP-SIM: Receive start response");

        if (attr->identity) {
                os_free(sm->identity);
                sm->identity = os_malloc(attr->identity_len);
                if (sm->identity) {
                        os_memcpy(sm->identity, attr->identity,
                                  attr->identity_len);
                        sm->identity_len = attr->identity_len;
                }
        }

        identity = NULL;
        identity_len = 0;

        if (sm->identity && sm->identity_len > 0 &&
            sm->identity[0] == EAP_SIM_PERMANENT_PREFIX) {
                identity = sm->identity;
                identity_len = sm->identity_len;
        } else {
                identity = eap_sim_db_get_permanent(sm->eap_sim_db_priv,
                                                    sm->identity,
                                                    sm->identity_len,
                                                    &identity_len);
                if (identity == NULL) {
                        data->reauth = eap_sim_db_get_reauth_entry(
                                sm->eap_sim_db_priv, sm->identity,
                                sm->identity_len);
                        if (data->reauth) {
                                wpa_printf(MSG_DEBUG, "EAP-SIM: Using fast "
                                           "re-authentication");
                                identity = data->reauth->identity;
                                identity_len = data->reauth->identity_len;
                                data->counter = data->reauth->counter;
                                os_memcpy(data->mk, data->reauth->mk,
                                          EAP_SIM_MK_LEN);
                        }
                }
        }

        if (identity == NULL) {
                wpa_printf(MSG_DEBUG, "EAP-SIM: Could not get proper permanent"
                           " user name");
                eap_sim_state(data, FAILURE);
                return;
        }

        wpa_hexdump_ascii(MSG_DEBUG, "EAP-SIM: Identity",
                          identity, identity_len);

        if (data->reauth) {
                eap_sim_state(data, REAUTH);
                return;
        }

        if (attr->nonce_mt == NULL || attr->selected_version < 0) {
                wpa_printf(MSG_DEBUG, "EAP-SIM: Start/Response missing "
                           "required attributes");
                eap_sim_state(data, FAILURE);
                return;
        }

        if (!eap_sim_supported_ver(data, attr->selected_version)) {
                wpa_printf(MSG_DEBUG, "EAP-SIM: Peer selected unsupported "
                           "version %d", attr->selected_version);
                eap_sim_state(data, FAILURE);
                return;
        }

        data->counter = 0; /* reset re-auth counter since this is full auth */
        data->reauth = NULL;

        data->num_chal = eap_sim_db_get_gsm_triplets(
                sm->eap_sim_db_priv, identity, identity_len,
                EAP_SIM_MAX_CHAL,
                (u8 *) data->rand, (u8 *) data->kc, (u8 *) data->sres, sm);
        if (data->num_chal == EAP_SIM_DB_PENDING) {
                wpa_printf(MSG_DEBUG, "EAP-SIM: GSM authentication triplets "
                           "not yet available - pending request");
                sm->method_pending = METHOD_PENDING_WAIT;
                return;
        }
        if (data->num_chal < 2) {
                wpa_printf(MSG_INFO, "EAP-SIM: Failed to get GSM "
                           "authentication triplets for the peer");
                eap_sim_state(data, FAILURE);
                return;
        }

        identity_len = sm->identity_len;
        while (identity_len > 0 && sm->identity[identity_len - 1] == '\0') {
                wpa_printf(MSG_DEBUG, "EAP-SIM: Workaround - drop last null "
                           "character from identity");
                identity_len--;
        }
        wpa_hexdump_ascii(MSG_DEBUG, "EAP-SIM: Identity for MK derivation",
                          sm->identity, identity_len);

        os_memcpy(data->nonce_mt, attr->nonce_mt, EAP_SIM_NONCE_MT_LEN);
        WPA_PUT_BE16(ver_list, EAP_SIM_VERSION);
        eap_sim_derive_mk(sm->identity, identity_len, attr->nonce_mt,
                          attr->selected_version, ver_list, sizeof(ver_list),
                          data->num_chal, (const u8 *) data->kc, data->mk);
        eap_sim_derive_keys(data->mk, data->k_encr, data->k_aut, data->msk,
                            data->emsk);

        eap_sim_state(data, CHALLENGE);
}


static void eap_sim_process_challenge(struct eap_sm *sm,
                                      struct eap_sim_data *data,
                                      struct wpabuf *respData,
                                      struct eap_sim_attrs *attr)
{
        const u8 *identity;
        size_t identity_len;

        if (attr->mac == NULL ||
            eap_sim_verify_mac(data->k_aut, respData, attr->mac,
                               (u8 *) data->sres,
                               data->num_chal * EAP_SIM_SRES_LEN)) {
                wpa_printf(MSG_WARNING, "EAP-SIM: Challenge message "
                           "did not include valid AT_MAC");
                eap_sim_state(data, FAILURE);
                return;
        }

        wpa_printf(MSG_DEBUG, "EAP-SIM: Challenge response includes the "
                   "correct AT_MAC");
        if (sm->eap_sim_aka_result_ind && attr->result_ind) {
                data->use_result_ind = 1;
                data->notification = EAP_SIM_SUCCESS;
                eap_sim_state(data, NOTIFICATION);
        } else
                eap_sim_state(data, SUCCESS);

        identity = eap_sim_db_get_permanent(sm->eap_sim_db_priv, sm->identity,
                                            sm->identity_len, &identity_len);
        if (identity == NULL) {
                identity = sm->identity;
                identity_len = sm->identity_len;
        }

        if (data->next_pseudonym) {
                eap_sim_db_add_pseudonym(sm->eap_sim_db_priv, identity,
                                         identity_len,
                                         data->next_pseudonym);
                data->next_pseudonym = NULL;
        }
        if (data->next_reauth_id) {
                eap_sim_db_add_reauth(sm->eap_sim_db_priv, identity,
                                      identity_len,
                                      data->next_reauth_id, data->counter + 1,
                                      data->mk);
                data->next_reauth_id = NULL;
        }
}


static void eap_sim_process_reauth(struct eap_sm *sm,
                                   struct eap_sim_data *data,
                                   struct wpabuf *respData,
                                   struct eap_sim_attrs *attr)
{
        struct eap_sim_attrs eattr;
        u8 *decrypted = NULL;
        const u8 *identity, *id2;
        size_t identity_len, id2_len;

        if (attr->mac == NULL ||
            eap_sim_verify_mac(data->k_aut, respData, attr->mac, data->nonce_s,
                               EAP_SIM_NONCE_S_LEN)) {
                wpa_printf(MSG_WARNING, "EAP-SIM: Re-authentication message "
                           "did not include valid AT_MAC");
                goto fail;
        }

        if (attr->encr_data == NULL || attr->iv == NULL) {
                wpa_printf(MSG_WARNING, "EAP-SIM: Reauthentication "
                           "message did not include encrypted data");
                goto fail;
        }

        decrypted = eap_sim_parse_encr(data->k_encr, attr->encr_data,
                                       attr->encr_data_len, attr->iv, &eattr,
                                       0);
        if (decrypted == NULL) {
                wpa_printf(MSG_WARNING, "EAP-SIM: Failed to parse encrypted "
                           "data from reauthentication message");
                goto fail;
        }

        if (eattr.counter != data->counter) {
                wpa_printf(MSG_WARNING, "EAP-SIM: Re-authentication message "
                           "used incorrect counter %u, expected %u",
                           eattr.counter, data->counter);
                goto fail;
        }
        os_free(decrypted);
        decrypted = NULL;

        wpa_printf(MSG_DEBUG, "EAP-SIM: Re-authentication response includes "
                   "the correct AT_MAC");
        if (sm->eap_sim_aka_result_ind && attr->result_ind) {
                data->use_result_ind = 1;
                data->notification = EAP_SIM_SUCCESS;
                eap_sim_state(data, NOTIFICATION);
        } else
                eap_sim_state(data, SUCCESS);

        if (data->reauth) {
                identity = data->reauth->identity;
                identity_len = data->reauth->identity_len;
        } else {
                identity = sm->identity;
                identity_len = sm->identity_len;
        }

        id2 = eap_sim_db_get_permanent(sm->eap_sim_db_priv, identity,
                                       identity_len, &id2_len);
        if (id2) {
                identity = id2;
                identity_len = id2_len;
        }

        if (data->next_pseudonym) {
                eap_sim_db_add_pseudonym(sm->eap_sim_db_priv, identity,
                                         identity_len, data->next_pseudonym);
                data->next_pseudonym = NULL;
        }
        if (data->next_reauth_id) {
                eap_sim_db_add_reauth(sm->eap_sim_db_priv, identity,
                                      identity_len, data->next_reauth_id,
                                      data->counter + 1, data->mk);
                data->next_reauth_id = NULL;
        } else {
                eap_sim_db_remove_reauth(sm->eap_sim_db_priv, data->reauth);
                data->reauth = NULL;
        }

        return;

fail:
        eap_sim_state(data, FAILURE);
        eap_sim_db_remove_reauth(sm->eap_sim_db_priv, data->reauth);
        data->reauth = NULL;
        os_free(decrypted);
}


static void eap_sim_process_client_error(struct eap_sm *sm,
                                         struct eap_sim_data *data,
                                         struct wpabuf *respData,
                                         struct eap_sim_attrs *attr)
{
        wpa_printf(MSG_DEBUG, "EAP-SIM: Client reported error %d",
                   attr->client_error_code);
        if (data->notification == EAP_SIM_SUCCESS && data->use_result_ind)
                eap_sim_state(data, SUCCESS);
        else
                eap_sim_state(data, FAILURE);
}


static void eap_sim_process_notification(struct eap_sm *sm,
                                         struct eap_sim_data *data,
                                         struct wpabuf *respData,
                                         struct eap_sim_attrs *attr)
{
        wpa_printf(MSG_DEBUG, "EAP-SIM: Client replied to notification");
        if (data->notification == EAP_SIM_SUCCESS && data->use_result_ind)
                eap_sim_state(data, SUCCESS);
        else
                eap_sim_state(data, FAILURE);
}


static void eap_sim_process(struct eap_sm *sm, void *priv,
                            struct wpabuf *respData)
{
        struct eap_sim_data *data = priv;
        const u8 *pos, *end;
        u8 subtype;
        size_t len;
        struct eap_sim_attrs attr;

        pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_SIM, respData, &len);
        if (pos == NULL || len < 3)
                return;

        end = pos + len;
        subtype = *pos;
        pos += 3;

        if (eap_sim_parse_attr(pos, end, &attr, 0, 0)) {
                wpa_printf(MSG_DEBUG, "EAP-SIM: Failed to parse attributes");
                eap_sim_state(data, FAILURE);
                return;
        }

        if (subtype == EAP_SIM_SUBTYPE_CLIENT_ERROR) {
                eap_sim_process_client_error(sm, data, respData, &attr);
                return;
        }

        switch (data->state) {
        case START:
                eap_sim_process_start(sm, data, respData, &attr);
                break;
        case CHALLENGE:
                eap_sim_process_challenge(sm, data, respData, &attr);
                break;
        case REAUTH:
                eap_sim_process_reauth(sm, data, respData, &attr);
                break;
        case NOTIFICATION:
                eap_sim_process_notification(sm, data, respData, &attr);
                break;
        default:
                wpa_printf(MSG_DEBUG, "EAP-SIM: Unknown state %d in "
                           "process", data->state);
                break;
        }
}


static Boolean eap_sim_isDone(struct eap_sm *sm, void *priv)
{
        struct eap_sim_data *data = priv;
        return data->state == SUCCESS || data->state == FAILURE;
}


static u8 * eap_sim_getKey(struct eap_sm *sm, void *priv, size_t *len)
{
        struct eap_sim_data *data = priv;
        u8 *key;

        if (data->state != SUCCESS)
                return NULL;

        key = os_malloc(EAP_SIM_KEYING_DATA_LEN);
        if (key == NULL)
                return NULL;
        os_memcpy(key, data->msk, EAP_SIM_KEYING_DATA_LEN);
        *len = EAP_SIM_KEYING_DATA_LEN;
        return key;
}


static u8 * eap_sim_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
{
        struct eap_sim_data *data = priv;
        u8 *key;

        if (data->state != SUCCESS)
                return NULL;

        key = os_malloc(EAP_EMSK_LEN);
        if (key == NULL)
                return NULL;
        os_memcpy(key, data->emsk, EAP_EMSK_LEN);
        *len = EAP_EMSK_LEN;
        return key;
}


static Boolean eap_sim_isSuccess(struct eap_sm *sm, void *priv)
{
        struct eap_sim_data *data = priv;
        return data->state == SUCCESS;
}


int eap_server_sim_register(void)
{
        struct eap_method *eap;
        int ret;

        eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
                                      EAP_VENDOR_IETF, EAP_TYPE_SIM, "SIM");
        if (eap == NULL)
                return -1;

        eap->init = eap_sim_init;
        eap->reset = eap_sim_reset;
        eap->buildReq = eap_sim_buildReq;
        eap->check = eap_sim_check;
        eap->process = eap_sim_process;
        eap->isDone = eap_sim_isDone;
        eap->getKey = eap_sim_getKey;
        eap->isSuccess = eap_sim_isSuccess;
        eap->get_emsk = eap_sim_get_emsk;

        ret = eap_server_method_register(eap);
        if (ret)
                eap_server_method_free(eap);
        return ret;
}
